Poultry production includes two major categories—meat production and egg production. Currently, most poultry produced in North America is grown under close control on highly specialized farms. The evolution from small flocks to large commercial units after World War II was facilitated by advances in the knowledge of nutrition, breeding, housing, disease control, processing of poultry and eggs, and by improvements in transportation and refrigeration that made possible distant marketing of fresh products.
Poultry produced for meat production is commonly referred to as broilers. During the last few decades, broiler production has greatly increased as a result of Americans becoming more health conscious as poultry is viewed by certain persons as healthier than other meats that are typically consumed. The increased broiler production also resulted from the increased demand for exports to other countries.
The poultry production facilities that are typically used in conjunction with commercial poultry production each contain a relatively large number of birds. For example, each poultry production facilities may house more than 20,000 birds.
The poultry production facilities confine the birds to protect them from predators and environmental extremes that would cause mortality or reduce growth, feed efficiency, immunocompetence, fertility or egg production. The poultry production facilities thereby facilitate efficiently managing a large volume of birds.
While the poultry production facilities enable a large volume of birds to be simultaneously raised, the large volume of birds generate waste materials that must be dealt with. One such material is airborne dust and biological particles.
Electrostatic precipitation of dust has been historically used to control emission from industrial smokestacks. This technique has also been used to remove dust from the air inside a living space.
When using electrostatic precipitation, ions placed into the treated airspace polarize any particles in the air. Thereafter, the polarized particles are removed from the air by attraction to a grounded collection plate.
Over time, a progressively thick layer of particles collect on the collection plate. This progressively thicker layer of particles reduces the efficiency of the electrostatic precipitation system because the layer of particles insulates the collection plate from the polarized airborne particles. To enhance the efficiency of the electrostatic precipitation system, it is necessary to periodically clean the collection plates to dislodge the accumulated particles.
Disadvantages of these types of electrostatic precipitation systems are that only a limited airspace may be treated by one collection plate. The cost and size of multiple collection plate systems reduces the feasibility of using electrostatic particle ionization in very dusty and larger air spaces.
Mitchell et al., U.S. Pat. No. 6,126,722, uses corona points to discharge negative ions into a large treated air space. This system relies on grounded surfaces inside and confining the air space to attract and hold the ionized particles.
While this system is effective at economically treating a large, dusty air space to reduce dust in the air, the polarized particles accumulate on the grounded surfaces and cause the grounded surfaces to become progressively more insulated, which decreases the efficiency of this system.
Even though manual and/or mechanical cleaning will maintain the desired ionization level, the cost and limited ability to manually or mechanically clean grounded surfaces makes such a system a less than optimal result.